ST. CLAIR SHORES, MI
On this page:
- What Has Been Done to Clean Up the Site?
- What Is the Current Site Status?
- Sampling and Monitoring
- Emergency Response and Removal
On related pages:
The Ten-Mile Drain (site map) (PDF) (1 pp, 571K, About PDF) in St. Clair Shores, Michigan, includes an underground storm sewer utility heavily contaminated with polychlorinated biphenyls (PCBs). A historical PCB release is believed to have migrated from a commercial parking lot onto adjacent properties and into and through the Ten Mile Drain storm sewer system (TMD system). The TMD system is approximately 15 feet below ground and discharges into two residential canals – the Lange and Revere Street canals – connected to Lake St. Clair. The canals provide recreational boating access to Lake St. Clair for approximately 125 homes and also are used for swimming and fishing.
What Has Been Done to Clean Up the Site?
Several removal actions, interim remedial actions and associated investigations have taken place since PCBs were first discovered at the site in 2001. Michigan Department of Environmental Quality (MDEQ), Macomb County Public Works Office (MCPWO), City of St. Clair Shores, Macomb County Health Department, and EPA’s removal response staff have done extensive cleanup, responded to residents’ concerns, and conducted investigations at the site.
Based on a second interim remedial action selected in 2014 to address high levels of PCBs, EPA set out to remove and replace two manhole vaults and the contaminated backfill around them near the intersection of Bon Brae Street and Harper Avenue that EPA believed were serving as a continuing source of PCBs to the rest of the TMD system and the canals. During the remedial action construction work in 2015, EPA expanded the remedial action to include the removal and replacement of the 120-foot-long pipe between the two manholes after PCB-contaminated oil was observed flowing from the pipe.
On July 10, 2014, EPA completed a time-critical removal of PCB-contaminated soil from nine residential properties and one commercial property. PCBs were found in the soil at or near the ground surface at these locations that was above EPA’s removal action criteria. About 1,500 tons of soil were removed and disposed in an offsite facility located in Wayne, Michigan.
In May 2014, EPA issued a second interim ROD (PDF) (73 pp, 107 MB, About PDF) based on the TMD site’s 2012 Source Area Investigation Report (PDF) (389 pp, 9.03 MB). This interim remedial decision would address the PCB contamination in the bedding and backfill materials at the base of two vaulted manholes believed to be serving as a continued source of PCBs to the rest of the TMD system and the Lange and Revere Street canals. It called for excavation, removal, and replacement of M7179 and J01 and the surrounding impacted backfill materials, proper off-site disposal of contaminated materials, installation of monitoring and recovery wells adjacent to the newly installed manhole vaults, and institutional controls (ICs) to prevent actions that could compromise the remedy.
For a complete list of site remedial and removal actions and community involvement activities see the site’s history timeline (PDF) (29 pp, 2.99 MB).
What Is the Current Site Status?
The U.S. Environmental Protection Agency is proposing to clean up PCB-contaminated soil at residential and commercial properties in the Ten-Mile Drain Superfund site, specifically in two areas of the site. The EPA’s proposed plan (PDF)(8 pp, 644) resulted from a study of the nature and extent of contamination at the site and an evaluation of the different cleanup options available. This proposed cleanup action involves selected properties in Investigation Area 1 around Lakeland and Bon Brae streets and Harper Avenue and Investigation Area 2 centered on the Lange and Revere Street canals as shown on this map (PDF) (1pp, 1.66 MB, About PDF). Based on data collected to-date, the near-surface soil cleanup addresses 25 known residential properties, part of a commercial property and three utility corridors as well as up to 100 properties that need to be tested in Investigation Areas 1 and 2. The recommended cleanup plan includes:
- Excavating near-surface soil with PCB concentrations exceeding selected cleanup levels.
- Off-site disposal of PCB-contaminated soil at an appropriate landfill.
EPA will not select a final cleanup plan until after it reviews comments received from the public at a hearing and during a public comment period (see Announcements and Key Topics). The Agency is issuing the proposed cleanup plan as part of its public participation responsibilities under the federal Superfund law. EPA may modify the proposed cleanup plan or select another option based on new information or public comments so your opinion is important.
Sampling and Monitoring
MDEQ conducted a site Investigation in July 2008 to document and obtain sufficient data to support listing the TMD site on the National Priorities List (NPL). EPA proposed the site for the NPL in March 2010 and finalized the site on the NPL in September 2010.
In April 2011, EPA began its source area investigation fieldwork in an attempt to find the source of the high PCB concentrations that were continuing to infiltrate the TMD system. The investigation focused on the sanitary sewer, gas, and water main utility corridors that crossed the TMD system utility corridor, which potentially could provide preferential pathways for PCB contamination to migrate into the TMD pipe. Utility lines are typically set in corridors backfilled with stone and other “loose” materials through which contamination could easily migrate. The source area investigation also included additional sampling within the TMD system utility corridor.
In August 2011, EPA designed and conducted a sediment sampling project in the Lange and Revere Street canals. Approximately 100 samples collected from the surface of the sediments and 40 samples collected from deeper sediments were analyzed for PCBs by an EPA mobile laboratory to characterize the contamination in the canals and provide information to explain the elevated PCB levels found in fish caught in the canals. Based on the findings of the 2011 sediment sampling event, the highest PCB concentrations were found near the TMD system outfall and ranged from 100 ppm to 570 ppm. The PCB concentrations decreased with depth and distance from the outfall.
In September 2011, EPA issued the first Interim Record of Decision (52 pp, 5.56 MB) for the TMD site to address the high concentrations of PCB-contaminated oil and sediments that continued to accumulate behind the weirs inside the TMD system.
EPA finalized its Source Area Investigation Report (389 pp, 9.03 MB) in January 2012. The results of the extensive investigation found significant concentrations of PCB-contaminated oil within the TMD system utility corridor backfill materials adjacent to four vaulted manhole locations: J01, M7179, M4335, and M7183. Importantly, only very low PCB concentrations were found in the backfill materials of the other utility corridors, ruling out the sanitary sewer, gas, and water main utility corridors as a source or conduit for the high PCB concentrations found at the TMD site. Additionally, PCBs were found in all depth intervals of the backfill materials near the intersection of Bon Brae Street and Harper Avenue, between Bon Brae and Lakeland Streets.
In August 2015, additional remedial investigation (RI) sampling was conducted focusing on the former Martin Drain (also known as the Old Martin Drain). The Martin Drain was an open, above-ground storm water drain. Historical Macomb County drain maps indicate that the former Martin Drain had flowed through the investigation area and discharged at the Rio Vista Canal located approximately three-quarters of a mile northeast of the Lange and Revere Street canals. Based on historical information, it appears that the former Martin Drain was backfilled after the TMD storm sewer was constructed in the mid-1960s. The objective of the sampling was to determine if the former Martin Drain was previously a migration pathway for PCB contamination. EPA completed approximately 34 borings within the former Martin Drain pathway on Bon Brae Street, B Street, and Jefferson Avenue. A total of 72 samples were analyzed for PCBs. Nineteen of the 34 cores sampled contained no detectable concentrations of PCBs. Based on the overall sample results, EPA determined that the former Martin Drain was likely a limited historical pathway for PCB migration.
Emergency Response and Removal
Cleanup included removal actions, or short-term cleanups, to address immediate threats to human health and the environment. EPA dredged the canals and cleaned out the underground storm sewer drain system. However, the contamination returned. As a result, in September 2010, EPA's work at the site shifted from the removal part of EPA's Superfund program to the remedial part, which focuses on long-term cleanup projects.